# Distributed under the OSI-approved BSD 3-Clause License. See accompanying
# file Copyright.txt or https://cmake.org/licensing for details.

#.rst:
# FindSDL2
# -------
#
# Locate SDL2 library
#
# This module defines
#
# ::
#
# SDL2_LIBRARY, the name of the library to link against
# SDL2_FOUND, if false, do not try to link to SDL
# SDL2_INCLUDE_DIR, where to find SDL.h
# SDL2_VERSION_STRING, human-readable string containing the version of SDL
#
#
#
# This module responds to the flag:
#
# ::
#
# SDL2_BUILDING_LIBRARY
# If this is defined, then no SDL2_main will be linked in because
# only applications need main().
# Otherwise, it is assumed you are building an application and this
# module will attempt to locate and set the proper link flags
# as part of the returned SDL2_LIBRARY variable.
#
#
#
# Don't forget to include SDLmain.h and SDLmain.m your project for the
# OS X framework based version. (Other versions link to -lSDLmain which
# this module will try to find on your behalf.) Also for OS X, this
# module will automatically add the -framework Cocoa on your behalf.
#
#
#
# Additional Note: If you see an empty SDL2_LIBRARY_TEMP in your
# configuration and no SDL2_LIBRARY, it means CMake did not find your SDL
# library (SDL.dll, libsdl.so, SDL.framework, etc). Set
# SDL2_LIBRARY_TEMP to point to your SDL library, and configure again.
# Similarly, if you see an empty SDLMAIN_LIBRARY, you should set this
# value as appropriate. These values are used to generate the final
# SDL2_LIBRARY variable, but when these values are unset, SDL2_LIBRARY
# does not get created.
#
#
#
# $SDL2DIR is an environment variable that would correspond to the
# ./configure --prefix=$SDL2DIR used in building SDL. l.e.galup 9-20-02
#
# Modified by Eric Wing. Added code to assist with automated building
# by using environmental variables and providing a more
# controlled/consistent search behavior. Added new modifications to
# recognize OS X frameworks and additional Unix paths (FreeBSD, etc).
# Also corrected the header search path to follow "proper" SDL
# guidelines. Added a search for SDLmain which is needed by some
# platforms. Added a search for threads which is needed by some
# platforms. Added needed compile switches for MinGW.
#
# On OSX, this will prefer the Framework version (if found) over others.
# People will have to manually change the cache values of SDL2_LIBRARY to
# override this selection or set the CMake environment
# CMAKE_INCLUDE_PATH to modify the search paths.
#
# Note that the header path has changed from SDL/SDL.h to just SDL.h
# This needed to change because "proper" SDL convention is #include
# "SDL.h", not <SDL/SDL.h>. This is done for portability reasons
# because not all systems place things in SDL/ (see FreeBSD).

find_package(PkgConfig)

if (PkgConfig_FOUND)
  pkg_search_module(SDL2 REQUIRED sdl2)
  set(SDL2_LIBRARIES ${SDL2_LDFLAGS})
endif()

if (NOT SDL2_FOUND)
  if(NOT SDL2_DIR)
    set(SDL2_DIR "" CACHE PATH "SDL2 directory")
  endif()

  find_path(SDL2_INCLUDE_DIR SDL.h
    HINTS
    ENV SDL2DIR
    ${SDL2_DIR}
    PATH_SUFFIXES SDL2
    # path suffixes to search inside ENV{SDL2DIR}
    include/SDL2 include
    )

  if(CMAKE_SIZEOF_VOID_P EQUAL 8)
    set(VC_LIB_PATH_SUFFIX lib/x64)
  else()
    set(VC_LIB_PATH_SUFFIX lib/x86)
  endif()

  find_library(SDL2_LIBRARY_TEMP
    NAMES SDL2
    HINTS
    ENV SDL2DIR
    ${SDL2_DIR}
    PATH_SUFFIXES lib ${VC_LIB_PATH_SUFFIX}
    )

  # Hide this cache variable from the user, it's an internal implementation
  # detail. The documented library variable for the user is SDL2_LIBRARY
  # which is derived from SDL2_LIBRARY_TEMP further below.
  set_property(CACHE SDL2_LIBRARY_TEMP PROPERTY TYPE INTERNAL)

  if(NOT SDL2_BUILDING_LIBRARY)
    if(NOT SDL2_INCLUDE_DIR MATCHES ".framework")
      # Non-OS X framework versions expect you to also dynamically link to
      # SDLmain. This is mainly for Windows and OS X. Other (Unix) platforms
      # seem to provide SDLmain for compatibility even though they don't
      # necessarily need it.
      find_library(SDL2MAIN_LIBRARY
        NAMES SDL2main
        HINTS
        ENV SDL2DIR
        ${SDL2_DIR}
        PATH_SUFFIXES lib ${VC_LIB_PATH_SUFFIX}
        PATHS
        /sw
        /opt/local
        /opt/csw
        /opt
        )
    endif()
  endif()

  # SDL may require threads on your system.
  # The Apple build may not need an explicit flag because one of the
  # frameworks may already provide it.
  # But for non-OSX systems, I will use the CMake Threads package.
  if(NOT APPLE)
    find_package(Threads)
  endif()

  # MinGW needs an additional link flag, -mwindows
  # It's total link flags should look like -lmingw32 -lSDLmain -lSDL -mwindows
  if(MINGW)
    set(MINGW32_LIBRARY mingw32 "-mwindows" CACHE STRING "link flags for MinGW")
  endif()

  if(SDL2_LIBRARY_TEMP)
    # For SDLmain
    if(SDL2MAIN_LIBRARY AND NOT SDL2_BUILDING_LIBRARY)
      list(FIND SDL2_LIBRARY_TEMP "${SDLMAIN_LIBRARY}" _SDL2_MAIN_INDEX)
      if(_SDL2_MAIN_INDEX EQUAL -1)
        set(SDL2_LIBRARY_TEMP "${SDLMAIN_LIBRARY}" ${SDL2_LIBRARY_TEMP})
      endif()
      unset(_SDL2_MAIN_INDEX)
    endif()

    # For OS X, SDL uses Cocoa as a backend so it must link to Cocoa.
    # CMake doesn't display the -framework Cocoa string in the UI even
    # though it actually is there if I modify a pre-used variable.
    # I think it has something to do with the CACHE STRING.
    # So I use a temporary variable until the end so I can set the
    # "real" variable in one-shot.
    if(APPLE)
      set(SDL2_LIBRARY_TEMP ${SDL2_LIBRARY_TEMP} "-framework Cocoa")
    endif()

    # For threads, as mentioned Apple doesn't need this.
    # In fact, there seems to be a problem if I used the Threads package
    # and try using this line, so I'm just skipping it entirely for OS X.
    if(NOT APPLE)
      set(SDL2_LIBRARY_TEMP ${SDL2_LIBRARY_TEMP} ${CMAKE_THREAD_LIBS_INIT})
    endif()

    # For MinGW library
    if(MINGW)
      set(SDL2_LIBRARY_TEMP ${MINGW32_LIBRARY} ${SDL2_LIBRARY_TEMP})
    endif()

    # Set the final string here so the GUI reflects the final state.
    set(SDL2_LIBRARY ${SDL2_LIBRARY_TEMP} CACHE STRING "Where the SDL Library can be found")
  endif()

  if(SDL2_INCLUDE_DIR AND EXISTS "${SDL2_INCLUDE_DIR}/SDL2_version.h")
    file(STRINGS "${SDL2_INCLUDE_DIR}/SDL2_version.h" SDL2_VERSION_MAJOR_LINE REGEX "^#define[ \t]+SDL2_MAJOR_VERSION[ \t]+[0-9]+$")
    file(STRINGS "${SDL2_INCLUDE_DIR}/SDL2_version.h" SDL2_VERSION_MINOR_LINE REGEX "^#define[ \t]+SDL2_MINOR_VERSION[ \t]+[0-9]+$")
    file(STRINGS "${SDL2_INCLUDE_DIR}/SDL2_version.h" SDL2_VERSION_PATCH_LINE REGEX "^#define[ \t]+SDL2_PATCHLEVEL[ \t]+[0-9]+$")
    string(REGEX REPLACE "^#define[ \t]+SDL2_MAJOR_VERSION[ \t]+([0-9]+)$" "\\1" SDL2_VERSION_MAJOR "${SDL2_VERSION_MAJOR_LINE}")
    string(REGEX REPLACE "^#define[ \t]+SDL2_MINOR_VERSION[ \t]+([0-9]+)$" "\\1" SDL2_VERSION_MINOR "${SDL2_VERSION_MINOR_LINE}")
    string(REGEX REPLACE "^#define[ \t]+SDL2_PATCHLEVEL[ \t]+([0-9]+)$" "\\1" SDL2_VERSION_PATCH "${SDL2_VERSION_PATCH_LINE}")
    set(SDL2_VERSION_STRING ${SDL2_VERSION_MAJOR}.${SDL2_VERSION_MINOR}.${SDL2_VERSION_PATCH})
    unset(SDL2_VERSION_MAJOR_LINE)
    unset(SDL2_VERSION_MINOR_LINE)
    unset(SDL2_VERSION_PATCH_LINE)
    unset(SDL2_VERSION_MAJOR)
    unset(SDL2_VERSION_MINOR)
    unset(SDL2_VERSION_PATCH)
  endif()

  set(SDL2_LIBRARIES ${SDL2_LIBRARY} ${SDL2MAIN_LIBRARY})
  set(SDL2_INCLUDE_DIRS ${SDL2_INCLUDE_DIR})

  include(FindPackageHandleStandardArgs)

  FIND_PACKAGE_HANDLE_STANDARD_ARGS(SDL2
    REQUIRED_VARS SDL2_LIBRARY SDL2_INCLUDE_DIR
    VERSION_VAR SDL2_VERSION_STRING)
endif()
